Comparison optical system

ABSTRACT

A comparison optical system ( 1 ) comprising several image-acquiring optical subsystems is disclosed. A bridge ( 3 ) mechanically and optically connects the optical subsystems to one another. Each of the image-acquiring optical subsystems possesses an XYZ stage ( 8   a   , 8   b ), movable in motorized fashion, on which a sample to be examined is placed. Also provided is a control unit which moves the XYZ stages ( 8   a   , 8   b ), movable in motorized fashion, synchronously in all three spatial directions. The synchronous motion of the XYZ stages ( 8   a   , 8   b ) can be switched on and off by the user.

RELATED APPLICATIONS

[0001] This application claims priority of the European patentapplication 02 102 514.3 which is incorporated by reference herein.

FIELD OF THE INVENTION

[0002] The invention concerns a comparison optical system. The inventionconcerns in particular a comparison optical system having severalimage-acquiring optical subsystems that are connected to one another viaa bridge which mechanically and optically connects the severalimage-acquiring optical subsystems to one another.

BACKGROUND OF THE INVENTION

[0003] German Patent DE 30 06 379 discloses a defect inspection systemfor comparative inspection of a standard specimen and a test item. Thetest item and the standard specimen are on a common support, and boththe standard specimen and the test item are imaged via optical means andcombined so that a comparison is possible.

[0004] German Unexamined Application DE 41 03 457 describes a comparisonmicroscope for viewing two similar specimens through two objectives,having a device which is configured for combining the two images forcomparative viewing. Each of the two objectives is part of an individualmicroscope, a video mixing apparatus, to which the video signals of twovideo cameras acquiring the images from the microscopes are conveyed,being provided as the device for combining the two images. Synchronousdisplacement of the microscope stages has not been acknowledged.

[0005] U.S. Pat. No. 4,403,839 describes a comparison optical devicethat is embodied for simultaneous observation of two specimens. A bridgeencompasses the optical means for combining the beam paths that aregenerated by the microscope or macroscope. Illuminating light isintroduced into the system by means of the photo tube. The document doesnot mention how the individual specimens must be arranged on one or morestages.

[0006] These macroscopes or microscopes described above are used incorresponding systems, which are embodied as comparison microscopes orcomparison macroscopes, for performing forensic comparativeexaminations. In a very well-known embodiment, two individualmicroscopes or individual macroscopes, connected to one another by abridge, are used. The bridge contains an apparatus for combining the twoindividual images generated by the individual microscopes ormacroscopes. Through a common tube arranged on the bridge, the operatorof the comparison microscope or macroscope can view in superimposedfashion the images of specimens arranged on two different stages.Appropriate blocking of portions of the two samples corresponding to oneanother yields a composite image which makes possible a directcomparison, for example, of one sample half to the other sample half.

[0007] In forensic investigations, crime-solving often requires that animage of a first sample be compared to the image of a second sample inorder to obtain more detailed information about the circumstances of acrime.

[0008] The specimens compared to one another are, for example, theimpressions produced on cartridge cases by the firing pin of a weapon,in order to determine whether the same firearm was used in two or morecrimes.

[0009] A further known application of optical comparison investigationsconsists in checking the authenticity of documents, especiallybanknotes, in order to determine whether they are counterfeit.

[0010] Lastly, crime-solving often requires comparing, for example,clothing fibers found at the crime scene to fibers of known articles ofclothing, in order to obtain information about how a perpetrator wasdressed at the time of a crime.

SUMMARY OF THE INVENTION

[0011] It is the object of the invention to create a comparison opticalsystem that is configured in user-friendly fashion and providesreproducible results.

[0012] This object is achieved by way of a comparison optical systemcomprising:

[0013] several image-acquiring optical subsystems

[0014] a bridge which connects the several image-acquiring opticalsubsystems mechanically and optically to one another,

[0015] an XYZ stage, movable in motorized fashion, is provided for eachimage-acquiring optical subsystem, and

[0016] a control unit for moving the XYZ stages in motorized fashion,synchronously in all three spatial directions.

[0017] The above object is as well achieved by a comparison opticalsystem comprising:

[0018] two macroscopes,

[0019] a bridge which connects the two macroscopes mechanically andoptically to one another,

[0020] an XYZ stage, movable in motorized fashion, is provided for eachmacroscope, and

[0021] a control unit for moving the XYZ stages in motorized fashion,synchronously in all three spatial directions.

[0022] The above object is as well achieved by a comparison opticalsystem comprising:

[0023] two microscopes,

[0024] a bridge which connects the two microscopes mechanically andoptically to one another,

[0025] an XYZ stage, movable in motorized fashion, is provided for eachmicroscope, and

[0026] a control unit for moving the XYZ stages in motorized fashion,synchronously in all three spatial directions.

[0027] The invention has the advantage that each image-acquiring opticalsubsystem possesses a XYZ stage, movable in motorized fashion, on whicha sample to be examined is placed. Also provided is a control unit thatmoves the XYZ stages (8 a, 8 b), movable in motorized fashion,synchronously in all three spatial directions. If the comparison opticalsystems are embodied as macroscopes, the control unit is embodied as acontrol and adjustment apparatus on which is provided an on/off switchwith which synchronous displacement of the XYZ stages can be switched onand off. Synchronous displacement has the advantage that upon actuationof an actuation element for a motion direction of an XYZ stage, both XYZstages are displaced in exactly uniform synchronous fashion. Themacroscopes can likewise each have associated with them a remote controldevice that can be used for stage and focus control. It is also possibleto activate the stage and focus control systems of the two remotecontrol devices in such a way that a synchronous motion is possible. Thecomparison optical system can likewise be constructed from microscopes.In this case a remote control device is connected to each microscope andcan be activated so as to make possible, for example by actuation of anactuation element of the remote control device, synchronous displacementof the XYZ stages that are mounted on the microscope stand. Thestructures present on the specimens to be examined are often larger interms of dimension than the region which is visible in the eyepiece orwith the attached camera. In order to allow the entire specimen to becompared, both XYZ stages must be shifted synchronously in the Xdirection, Y direction, and Z direction. With synchronous displacementit is possible to shift the two XYZ stages synchronously using only oneX actuation element or Y actuation element or the Z fine displacementcontrol for each of the X, Y, and Z axes respectively. This has theadvantage that evaluation of the specimens to be examined isconsiderably improved. A prerequisite for synchronization is that atleast the three axes of the XYZ stages be motorized.

[0028] Further advantageous embodiments of the invention are evidentfrom the dependent claims.

BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The subject matter of the invention is depicted schematically inthe drawings and will be described below with reference to the Figures,in which:

[0030]FIG. 1 is a perspective view of a first embodiment of thecomparison optical system, the optical subsystems being embodied asmacroscopes;

[0031]FIG. 2 is a perspective view of a second embodiment of thecomparison optical system, the optical subsystems being embodied asmicroscopes; and

[0032]FIG. 3 is a detail view of a control unit with which the XYZstages of the comparison optical system are synchronously movable.

DETAILED DESCRIPTION OF THE INVENTION

[0033]FIG. 1 shows a comparison optical system 1. In this embodiment,comparison optical system 1 comprises a first and a second macroscope 2a and 2 b that are configured as image-acquiring optical subsystems.First and second macroscope 2 a and 2 b are mechanically and opticallyconnected to one another via a bridge 3. Bridge 3 possesses a viewingport 4 for a user, and a tube 5 having a connection 6 for a camera (notdepicted). Viewing port 4 for the user can be configured pivotably inorder to maintain an ergonomic working position for the user. Tube 5 canadditionally possess a further connection 7 with which, for example, asecond camera (not depicted) can be attached. A first XYZ stage 8 a isassociated with first macroscope 2 a. A second XYZ stage 8 b isassociated with second macroscope 2 b. A specimen to be compared (notdepicted) is placed respectively on first and on second XYZ stage 8 aand 8 b. In comparison macroscopy, both bullets and tools are assessedas specimens, and the traces left thereby are optically compared to oneanother and evaluated. This is done, in most cases, by splitting theimage in the middle so that the specimen positioned on first XYZ stage 8a is visible in the left half, and the specimen positioned on second XYZstage 8 b is visible in the right half.

[0034] Bridge 3, together with first and second XYZ stage 8 a and 8 b,is mounted on a column 10 via a dovetail guide 11. By verticaldisplacement of column 10, bridge 3 is displaceable in the Z direction,or vertically, relative to the surface of XYZ stages 8 a and 8 b. Themovement of bridge 3 allows coarse focusing of the specimens, present onthe two stages 8 a and 8 b, whose structures are to be compared. Column10 itself is joined to a base 12 which is substantially wider thancolumn 10 in order to achieve sufficient stability and steadiness forcomparison optical system 1. Arranged between the first and on thesecond XYZ stage 8 a and 8 b is a control and adjustment apparatus 14with which various functions of comparison optical system 1 can beadjusted or modified. Control and adjustment apparatus 14 possessesseveral actuation elements (see FIG. 3 for description) with whichvarious functions of comparison optical system 1 can be actuated. It isself-evident that control and adjustment apparatus 14 depicted in FIG. 1can be variously embodied.

[0035] The two XYZ stages 8 a and 8 b are displaceable in the Xdirection, Y direction, and Z direction by way of several motors 16. Afirst and a second remote control device 18 a and 18 b can moreover alsobe associated with comparison optical system 1. In this embodiment, thefirst and a second remote control device 18 a and 18 b are eachconnected to comparison optical system 1 via a cable 19. Remote controldevices 18 a and 18 b each possess a plurality of actuation elements 24that can be assigned for various motorized functions of comparisonoptical system 1. It is self-evident that the connection can assume anytechnical configuration, for example radio, infrared, etc. Comparisonoptical system 1 can additionally have associated with it a PC 20 that,via an RS232 cable or USB cable 21, supplies control signals tocomparison optical system 1 and receives image data or settings datafrom comparison optical system 1. The image data are displayed to theuser on a monitor 22 that is connected to PC 20. The current settingsdata of comparison optical system 1 can also be displayed to the user onmonitor 22.

[0036]FIG. 2 is a perspective view of a second embodiment of comparisonoptical system 1, the optical subsystems comprising, in this embodiment,a first and a second microscope 30 a and 30 b. Elements that correspondto the elements in FIG. 1 are labeled with the same referencecharacters. First and second microscope 30 a and 30 b are connected toone another via a bridge 3. Each microscope 30 a and 30 b comprises astand that comprises a base 32. Base 32 is subdivided into three mainsegments, made up of a transverse main segment 34, a stand columnsegment 36, and a stand foot segment 35. An XYZ stage 8 a, 8 b ismounted on stand column segment 36. Each microscope 30 a and 30 b isequipped with a transmitted-light illumination system and anincident-light illumination system (both not depicted).

[0037] Stand foot segment 35 is convexly curved in the region facingtoward stand column segment 36, and possesses a display 40 in convexlycurved region 37. Display 40 can also be embodied as a touch screenwhich allows the user to make parameter inputs and call certainmeasurement methods therewith. If display 40 is not embodied as a touchscreen, current settings data of the respective microscope 30 a or 30 bare then visually presented via display 40. Additionally mounted on eachmicroscope 30 a and 30 b is a respective drive knob 42 which, forexample, displaces XYZ stage 8 a or 8 b associated with each microscope30 a or 30 b vertically (in the Z direction). It is likewise conceivableadditionally to assign other functions to drive knob 42. Multipleactuation elements 44 with which microscope functions can also beswitched are provided in the region around drive knob 42. The microscopefunctions are, for example, filter changing, aperture selection,revolving turret movement, etc.

[0038] Bridge 3 is attached to connecting element 50 a and 50 b of eachmicroscope 30 a and 30 b. Analogously to FIG. 1, bridge 3 possesses aviewing port 4 for a user, and a tube 5 having a connection 6 for acamera (not depicted). Viewing port 4 for the user can be configuredpivotably in order to maintain an ergonomic working position for theuser. Both XYZ stages 8 a and 8 b are displaceable in the X direction, Ydirection, and Z direction by way of several motors 16. Analogously toFIG. 1, first and second remote control device 18 a and 18 b are alsoassociated with comparison optical system 1. These are each connectedvia a cable 19 to comparison optical system 1 or to PC 20. It isself-evident that the connection can assume any technical configuration,for example radio, infrared, etc. A display 22 is additionallyassociated with PC 20.

[0039]FIG. 3 is a detail view of control and adjustment apparatus 14 ofFIG. 1, with which XYZ stages 8 a and 8 b of the comparison opticalsystem are synchronously movable. Control and adjustment apparatus 14encompasses a plurality of adjusting elements for comparison opticalsystem 1. Provided on a front side 14 a of control and adjustmentapparatus 14 is a switch 60, actuation of which causes a verticaldisplacement of column 10 (FIG. 1). This results in coarse focusing onthe specimens that are present on XYZ stages 8 a and 8 b of comparisonoptical system 1 of FIG. 1. Directly above switch 60 is an on/off switch61 for synchronous displacement of the two XYZ stages 8 a and 8 b. Tothe left of switch 60 is an X actuation element 62 a for displacingfirst XYZ stage 8 a in the X direction. To the right of switch 60 is anX actuation element 62 b for displacing second XYZ stage 8 b in the Xdirection. Provided above X actuation element 62 a is an adjustmentelement 63 a for an illumination system, with which the light intensityof an external light source (not depicted) can be modified. Similarly,above X actuation element 62 b is an adjustment element 63 b for anillumination system, with which the light intensity of an external lightsource (not depicted), whose light is directed onto second XYZ stage 8b, can be modified.

[0040] In FIG. 3, only a first lateral surface 14 b of control andadjustment apparatus 14 is depicted visibly. On first lateral surface 14b is a Y actuation element 64 b for displacing second XYZ stage 8 b inthe Y direction. Also provided on first lateral surface 14 b is a Z finedisplacement control 65 b for second XYZ stage 8 b in the Z direction. AZ fine displacement control 65 a for first XYZ stage 8 a is provided onsecond lateral surface 14 c.

[0041] Control and adjustment apparatus 14 furthermore possesses a topsurface 14 d on which are mounted several actuation elements 70, 71, 72,73, 74, 75, and 76 which are provided for modification of the imagedepiction. Actuation element 70 serves to generate a superimposed image,the image of the specimen on first XYZ stage 8 a being overlaid on thespecimen on second XYZ stage 8 b. Actuation element 71 serves togenerate a side-by-side depiction of the specimen on first XYZ stage 8 anext to the specimen on second XYZ stage 8 b. Actuation element 72serves to generate a depiction of the image of the specimen on first XYZstage 8 a. Actuation element 73 serves to generate a depiction of theimage of the specimen on second XYZ stage 8 b. Actuation element 74 isused for manual aperture matching. Actuation element 75 is used formanual lateral shifting of the apertures. Actuation element 76 is usedfor secondary magnification of the specimens to be depicted. In aparticular embodiment, a 1.5× magnification is provided.

[0042] An on/off switch 61 for synchronous displacement of the two XYZstages 8 a and 8 b is configured in such a way that the functioning ofthe control elements is coupled, so that the previously independent Xactuation elements 62 a and 62 b, Y actuation elements 64 a and 64 b,and Z fine displacement controls 65 a and 65 b for each individual XYZstage 8 a and 8 b act synchronously on both XYZ stages 8 a and 8 b. Oncethe two XYZ stages 8 a and 8 b have been adjusted, the structures to beinvestigated are compared. These structures are often larger in terms oftheir dimensions than the region that is visible in the eyepiece or withthe attached camera. To allow the entire specimen to be compared, bothXYZ stages 8 a and 8 b must be shifted synchronously in the X direction,Y direction, and Z direction. It is thereby possible, using only one Xactuation element or Y actuation element or the Z fine displacementcontrol for each of the X, Y, and Z axes respectively, to displace thetwo XYZ stages 8 a and 8 b synchronously in order thereby to improve theevaluation of the specimens being investigated. In addition, theergonomics of the entire comparison optical system 1 is considerablyimproved. A prerequisite for synchronization is motorization of thethree axes of XYZ stages 8 a and 8 b. This applies both to macroscopes 2a and 2 b or microscopes 30 a and 30 b that are connected by bridge 3.

[0043] In addition to control and adjustment apparatus 14 formacroscopes 2 a and 2 b, the latter also have associated with them afirst remote control device and second remote control device 18 a and 18b. Once macroscopes 2 a and 2 b or microscopes 30 a and 30 b have beenadjusted in conventional fashion, the functioning of the actuationelements is coupled, by way of a button or a command from the PC (viaRS232, USB, etc.), in such a way that upon actuation of any actuationelement or the Z fine displacement control for a direction, both XYZstages are moved synchronously. It is now possible, for example via Xoperating element 62 b of second XYZ stage 8 b and X operating element62 a of first XYZ stage 8 a, to move both XYZ stages 8 a and 8 bsynchronously in the X direction. The same applies to the axes in the Yand Z directions.

[0044] As with comparison optical system 1 in which macroscopes 2 a and2 b are used, this function can be switched on by way of the built-inelectronic system. When two microscopes 30 a and 30 b made up of twoindependently functioning stands are combined with a bridge 3,electronic synchronization of XYZ stages 8 a and 8 b is thenaccomplished via interfaces or PC 20. As depicted in FIG. 2, firstmicroscope 30 a and second microscope 30 b have respectively associatedwith them a first remote control device 18 a and a second remote controldevice 18 b, which have actuation elements 24 for the X direction, Ydirection, and Z direction of each XYZ stage 8 a and 8 b. As withmacroscopes 2 a and 2 b, the synchronization makes it possible tocontrol both XYZ stages 8 a and 8 b of microscopes 30 a and 30 bsynchronously using only one remote control device 18 a or 18 b.

1. A comparison optical system comprising: several image-acquiringoptical subsystems a bridge which connects the several image-acquiringoptical subsystems mechanically and optically to one another, an XYZstage, movable in motorized fashion, is provided for eachimage-acquiring optical subsystem, and a control unit for moving the XYZstages in motorized fashion, synchronously in all three spatialdirections.
 2. The comparison optical system as defined in claim 1,wherein each of the image-acquiring optical subsystems is a macroscope.3. The comparison optical system as defined in claim 1, wherein each ofthe image-acquiring optical subsystems is a microscope.
 4. Thecomparison optical system as defined in claim 1 wherein twoimage-acquiring optical subsystems are mechanically and opticallycoupled with the bridge.
 5. The comparison optical system as defined inclaim 1, wherein at least for the displacement of the XYZ stages in theX direction, Y direction, and Z direction, a motor is provided whichreceives the signals of the control unit and converts them into acorresponding rotation.
 6. A comparison optical system comprising: twomacroscopes, a bridge which connects the two macroscopes mechanicallyand optically to one another, an XYZ stage, movable in motorizedfashion, is provided for each macroscope, and a control unit for movingthe XYZ stages in motorized fashion, synchronously in all three spatialdirections.
 7. The comparison optical system as defined in claim 6,wherein the control unit is a control and adjustment apparatus that isassociated with the macroscopes.
 8. The comparison optical system asdefined in claim 5, wherein the control unit is a control and adjustmentapparatus that is associated with the macroscopes; and a first remotecontrol device is respectively connected to the first macroscope; and asecond remote control device is connected to the second macroscope. 9.The comparison optical system as defined in claim 8, wherein the controland adjustment apparatus possesses an X actuation element fordisplacement of the first XYZ stage and an X actuation element fordisplacement of the second XYZ stage, a Y actuation element fordisplacement of the first XYZ state and a Y actuation element fordisplacement of the second XYZ stage, and a Z fine displacement controlfor the first XYZ stage and a Z fine displacement control for the secondXYZ stage.
 10. The comparison optical system as defined in claim 9,wherein the control and adjustment apparatus encompasses an on/offswitch for a synchronous displacement of the two XYZ stages which actsin such a way that when the on/off switch for synchronous displacementis switched on, both XYZ stages are movable synchronously regardless ofthe actuation of the X actuation element or X actuation element, the Yactuation element or Y actuation element, the Z fine displacementcontrol or the Z fine displacement control.
 11. The comparison opticalsystem as defined in claim 9, wherein the first remote control deviceand the second remote control device encompass a plurality of actuationelements; and the actuation elements of the first remote control deviceand of the second remote control device are also synchronizable inpairs.
 12. The comparison optical system as defined in claim 6, whereinthe comparison optical system has associated with it a PC that, via anRS232 cable or a USB cable, supplies control signals to the comparisonoptical system and receives image data or settings data from thecomparison optical system.
 13. A comparison optical system comprising:two microscopes, a bridge which connects the two microscopesmechanically and optically to one another, an XYZ stage, movable inmotorized fashion, is provided for each microscope, and a control unitfor moving the XYZ stages in motorized fashion, synchronously in allthree spatial directions.
 14. The comparison optical system as definedin claim 13, wherein the control unit is a first remote control devicethat is associated with the first microscope; and a second remotecontrol device is associated with the second microscope.
 15. Thecomparison optical system as defined in claim 13, wherein the controlunit is a control and adjustment apparatus which possesses an Xactuation element for displacement of the first XYZ stage and an Xactuation element for displacement of the second XYZ stage, a Yactuation element for displacement of the first XYZ state and a Yactuation element for displacement of the second XYZ stage, and a Z finedisplacement control for the first XYZ stage and a Z fine displacementcontrol for the second XYZ stage.
 16. The comparison optical system asdefined in claim 15, wherein the control and adjustment apparatusencompasses an on/off switch for a synchronous displacement of the twoXYZ stages which acts in such a way that when the on/off switch forsynchronous displacement is switched on, both XYZ stages are movablesynchronously regardless of the actuation of the X actuation element orX actuation element, the Y actuation element or Y actuation element, theZ fine displacement control or the Z fine displacement control.
 17. Thecomparison optical system as defined in claim 14, wherein the firstremote control device and the second remote control device encompass aplurality of actuation elements; and the actuation elements of the firstremote control device and of the second remote control device are alsosynchronizable in pairs.
 18. The comparison optical system as defined inclaim 13, wherein at least for the displacement of the XYZ stages in theX direction, Y direction, and Z direction, a motor is provided whichreceives the signals of the control unit and converts them into acorresponding rotation.
 19. The comparison optical system as defined inclaim 1, wherein the comparison optical system has associated with it aPC that, via an RS232 cable or a USB cable, supplies control signals tothe comparison optical system and receives image data or settings datafrom the comparison optical system.
 20. The comparison optical system asdefined in claim 13, wherein the synchronization of the XYZ stages canbe switched on and off by way of the PC (20).